For a mobile station subscriber that subscribes to and activates a do not disturb service on a mobile communication network, any calling party that places a telephone call to such subscriber will typically hear a fast busy signal. On the other hand, the mobile station of the subscriber will not ring or otherwise notify the subscriber of an incoming call because a mobile communication network does not establish a connection between the calling party and the subscriber when the feature is active. Instead, the communication network determines that the subscriber has activated the do not disturb service feature and plays the fast busy signal to the calling party.
FIG. 5 is a conventional flow diagram that illustrates a call process for a call placed to a mobile station of a subscriber that subscribes to and has activated the above-mentioned do not disturb service. The flow diagram illustrates the originating mobile switching center (O-MSC) and home location register (HLR) both of which are components of a mobile communication network (not shown) that supports the do not disturb feature. The subscriber's home HLR maintains the authorization status and activation status for the do not disturb service on a per-subscriber basis. When a call arrives at the called subscriber's home O-MSC (Step a), the O-MSC sends a query to the HLR for the subscriber's location (Step b). The query may be a location check request (“LOCREQ”) that includes information used to identify the called subscriber, such as the MSCID (the ID of the O-MSC), BILLID (the billing ID for the call), DGTSDIAL (digits identifying the called party), and TRIGTYPE (indicates that the a mobile termination trigger was encountered). The HLR accesses the subscriber profile record associated with the called party/station and examines the subscriber's list of services, which may include the do not disturb feature. If the called subscriber subscribes to and has activated the do not disturb feature, in Step c, the HLR returns to the O-MSC a message indicating that the LOCREQ has been denied. In turn in Step d the O-MSC sends a fast busy tone to the calling party. The O-MSC has no function to determine the actual reason for the denial of the LOCREQ. As a result, the fast busy tone sent by the O-MSC is the same tone sent to all callers in response to a LOCREQ being denied. Although the messages and/or signal flow may vary somewhat, similar do not disturb services are provided by landline and/or voice over packet protocol type telephone networks.
The do not disturb feature provides several advantages. When activated, it is not necessary to complete a call to the subscriber, which conserves network resources. Also, the subscriber is not disturbed, i.e., the called station of the subscriber does not ring or otherwise notify the subscriber of an incoming call. The calling party will hear a fast busy tone, thus indicating that the subscriber has activated the do not disturb feature (this assumes that the calling party knows the meaning of a fast busy tone).
The do not disturb feature however has limited functionality. For example, the called party will have no knowledge of the status of the called party other than that the called party has activated the do not disturb feature. For example, if the subscriber is on an airplane, the do not disturb feature does not permit informing a calling party of that situation. In such case, the calling party may repeatedly attempt to contact the subscriber until the subscriber deactivates the do not disturb feature. This results in an inconvenience to both the caller and the subscriber, especially if the caller leaves multiple voicemails which requires the subscriber to listen to such voicemails. Additionally, the subscriber is not able to inform others of the reason for activating a do not disturb feature. For example, the subscriber is unable to inform callers that he or she will be unavailable for a specified period of time because of air travel. In many situations, this ability may be very important for the subscriber. Also, some callers may not know of the called subscriber's do not disturb service and misinterpret the fast busy tone as a network busy or service outage indication.
The need thus exists for an improved means to indicate to a caller that a subscriber is busy. A further need exists to extend the capability of the communication network to provide calling parties more detailed status information of the subscriber.